(a) Technical Field
The present disclosure relates generally to an apparatus and a method for controlling torque reduction of a hybrid electric vehicle. More particularly, the present disclosure relates to an apparatus and a method for controlling torque reduction of a hybrid electric vehicle that maintains an engine torque according to an engine operating point and performs torque reduction by using a motor torque when a demand torque of a traction control system (TCS) is generated.
(b) Description of the Related Art
Generally, a hybrid electric vehicle is driven by an engine which generates torque from fuel combustion and an electric motor which generates torque from an electric battery. Hybrid electric vehicles can include a hybrid control unit (HCU) for controlling an engine operation of the hybrid electric vehicle, an engine control unit (ECU) for controlling an operation of an engine, a motor control unit (MCU) for controlling an operation of the driving motor, a transmission control unit (TCU) for controlling an operation of the transmission, and a battery management system (BMS) for managing a condition of a battery.
Meanwhile, a traction control system (TCS) is a safety system for preventing wheel spin and improving driving stability by controlling a brake and an engine while starting or accelerating. The TCS is mounted on the hybrid electric vehicle and requests torque reduction when wheel spin occurs while starting or accelerating.
Conventionally, if a demand torque of the TCS is generated when the TCS requests torque reduction, the hybrid electric vehicle decreases engine torque. Then, if the decreased engine torque cannot satisfy the demand torque of the TCS, the hybrid electric vehicle decreases motor torque to satisfy the demand torque of the TCS. However, in a case that the demand torque of the TCS is satisfied using the motor torque, a state of charge (SOC) of the battery is depleted. As a result, power performance of the motor deteriorates. Moreover, a demand torque of a driver cannot be satisfied after finishing an operation of the TCS, so the hybrid electric vehicle cannot smoothly start again.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the related art that is already known in this country to a person of ordinary skill in the art.